Characterizing nocturia among Belgian healthy postmenopausal women : prevalence, degree of bother, etiology and risk factors for nocturia

Introduction: Limited literature concerning nocturia in early postmenopausal women is available. However, due to the lack of endogenous estrogen in these women, an increased prevalence of nocturia is expected. Material and methods: This prospective observational trial recruited 210 'early' postmenopausal women consulting the Ghent University menopause clinic. Postmenopausal status was biochemically confirmed. Women completed 3 questionnaires: the ICI questionnaire on nocturia (ICIQ-N); 'Targeting the individual's Aetiology of Nocturia to Guide Outcomes' (TANGO) and the Perceived Stress Scale (PSS). Moreover, information concerning women's age, anthropometrics and lifestyle was collected. Nocturia was defined as two or more nocturnal voids. Results: Nocturia was reported in 24.8% (52/210) of the postmenopausal women. Bother increased with every nocturnal void. Women with two or more nighttime voids were found to have significantly increased prevalence of urgency compared with women with only one (p 0.001; 38.5% versus 22.7%). Trouble initiating sleep at the start of the night and insomnia during the night were significantly different in women with a different nocturnal frequency (initiating sleep p = 0.09, no voids 34.4 %, 1 void 39.2 %, 0.001; no voids 1.6%, 1 void 22.7 %, 2 voids 53.8 %). In addition to bladder and sleep dysfunctions, waist circumference was a risk factor for nocturia (OR 1.04; 95 % CI: 1.01-1.08). Conclusion: Nocturia is an important problem in early postmenopausal women, affecting a quarter of the questioned women. Etiology of nocturia in this population is multifactorial as estrogen withdrawal is accompanied by bladder and sleep dysfunctions